A fundamental question is the nature of the relationship between hormone binding to cellular elements in brain cells and the expression of behavioral responses. We will relate the binding of the ovarian hormones estradiol and progesterone to the display of sexual behaviors classified as receptive, proceptive and attractive and to non-sexual processes of weight regulation and taste preference which are also regulated by ovarian hormones. These sexual and non-sexual response systems are normally coordinated. However, to understand their hormonal regulation they must be dissociated. The dissociation of these systems will be achieved by manipulation of the sexual differentiation process by neonatal gonadectomy and the administration of androgens, estrogens, antiandrogens, antiestrogens and inhibitors of hormone metabolism. The hormonal regulation of the target behaviors will be evaluated by dose-response analyses of the actions of estrogen and progesterone. These animals will then be used to quantify the binding of estrogen and progesterone to selected regions of the brain using direct tracer and exchange assays of hormone binding. These studies will provide needed information on the translation of hormonal information into behavioral events.